Earthmoving scraper with multiple articulated apron structure



t. 14 1 R. A. PETERSON 0c EARTHMOVING SGRAPER WITH MULTIPLE ARTICULA'I'ED APRON STRUCTURE 5 Sheets-Sheet 1 Filed Oct. 27, 1966 INVENTORY ROBERT A. PETERSON 1 R. A. PETERSON Oct. EARTHMOVING SCRAPER WITH MULTIPLE ARTICULATED APRON STRUCTURE 3 Sheets-Sheet 2 Filed Oct. 27, 1966 ROBERT A PETERSON Oct. 14, 1969 PETERSON 3,471,952

EARTHMOVING SCRAPER WITH MULTIPLE ARTICULATED APRON STRUCTURE Filed Oct. 27, 1966 3 Sheets-Sheet 5 INVENTOR. ROBERT A. PETERSON United States Patent 3,471,952 EARTHMOVING SCRAPER WITH MULTIPLE ARTICULATED APRON STRUCTURE Robert A. Peterson, San Leandro, Calif., assignor to Caterpillar Tractor Co., Peoria, Ill., a corporation of California Filed Oct. 27, 1966, Ser. No. 589,978 lint. Cl. E02f 3/62, 3/64 U.S. Cl. 37-129 Claims ABSTRACT OF THE DISCLOSURE A self-loading scraper is provided with a manipulatable apron which is coupled to the bowl of the scraper through an articulated support frame having three pivot axes together with powered means for flexing the structure about each of the axes whereby the apron may be made to undergo a variety of motions to facilitate the movement of earth into the bowl, to facilitate the ejection of material therefrom, to reach out and draw large objects into the bowl and to effect still other operations.

This invention relates to earthworking equipment and more particularly to tractor drawn scrapers of the class having a load carrying bowl with a cutting edge of directing earth into the bowl. The invention provides a multiple jointed apron assembly which may be manipulated through a variety of movements to provide for self loading, to facilitate ejection, and for other purposes.

A conventional earthmoving scraper depends upon the forward motion of the vehicle to force earth from the cutting blade up into the load carrying bowl. As the contents of a partially filled bowl offers substantial resistance to the entrance of additional material it has usually been necessary to make use of a pusher tractor, in addition to the tractor which draws the scraper, in order to completely fill the bowl so that the full load carrying capacity of the scraper is utilized. As this practice is costly and inefiicient a variety of self loading scrapers have been developed.

The most commonly used form of self loading scraper is provided with a chain and flight elevator structure at the forward face of the bowl and above the cutting edge. The elevator functions to continually carry earth away from the immediate region of the cutting edge and thus lessens the resistance to entrance of additional soil into the bowl. Under many conditions, the elevator enables complete filling of the bowl without employing supplementary motive power,

However, elevator equipped self loading scrapers have been found to be subject to certain operating problems of their own. The elevator limits the size of the entrance opening into the bowl and thereby prevents the loading of boulders or other objects which are larger than some specific size. Further the elevator is particularly susceptible to jamming and damage from large boulders or other similar obstructions. Certain types of soils and soil conditions seriously interfere with elevator operation. Still another problem is encountered in that there are conditions under which the elevator will not insure full loading of the bowl and it becomes desirable to utilize a pusher tractor as with a conventional scraper. As the elevator partially obstructs the front of the scraper bowl, push loading is inefficient. Although multiple elevator speeds can be provided, the rate at which material is forced into the bowl by push loading is difiicult to coordinate with that of the elevator.

To avoid some of these problems a second general class of self loading scraper has heretofore been proposed. Instead of an elevator, such scrapers have an apron mounted at the open front of the bowl in such a manner that a it may be pivoted upward and downward and may be reciprocated in a horizontal direction. The apron may thus be made to undergo a kind of raking or hoeing motion to pull material into the bowl from the region of the blade. Scrapers of this class are not extensively used in the industry at present. This results at least in part from operational limitations of the apron manipulating mechanism as heretofore designed. The mechanism has been cumbersome while providing for only a very restricted variety of motions thereby limiting its utility for facilitating loading and preventing its use for other scraper operations.

The present invention is a scraper having a manipulatable apron mounted at the bowl by a multiple articulated structure with independent powered control of flexing at each joint so that the apron may be made to undergo a variety of movements within the bowl, above the bowl, and forwardly thereform. The extreme degree of manipulatability and the range of apron positions obtainable with this structure greatly facilitates a variety of scraper functions.

The apron of this invention may be readily manipulated to scoop material across the blade and into the bowl with any kind of a linear or curvilinear motion which may be appropriate to the circumstances and at any desired elevation with reference to the blade. The structure facilitates a kind of progressive loading in which the ejector is initially moved to a forward position in the bowl and loaded by the above described scooping action of the apron, after which the ejector is moved rearwardly carrying the contained material to the rear of the bowl and leaving the forward portion thereof available for receiving additional material. The apron may readily be lifted as high as might be necessary to receive boulders and other large objects into the bowl and may further be employed to reach forward and over such objects to forcibly load the object into the bowl.

The manipulatable apron may be lifted completely above the bowl during ejection of the load and may be moved down along the face of the ejector in a scraping movement to remove any lodged or sticky material therefrom,

Accordingly it is an object of this invention to provide a more versatile earthmoving scraper.

It is another object of this invention to provide a self loading scraper free from fixed mechanism restricting the opening at the load carrying bowl.

It is still another object of this invention to provide a more eflicient and flexible self loading mechanism for earth moving scrapers.

It is a further object of the invention to provide a self loading scraper which may be push loaded without complications or problems where soil conditions make such operation necessary.

It is still another object of the invention to provide a self loading mechanism for a scraper which may be completely lifted from the bowl of the scraper during ejection of the contents thereof and which may be utilized to facilitate such ejection.

Still a further object of this invention is to provide a self loading earthmoving scraper having powered mechanism for facilitating the loading of large boulders and similar objects.

An additional object of the invention is to provide a self loading mechanism for an earthmoving scraper which may be used in conjunction with the ejector thereof to facilitate complete filling of the bowl of the scraper.

The invention together with further objects and advantages thereof will best be understood by reference to the following specification in conjunction with the accompanying drawings of which:

FIGURE 1 is a side elevation view of the bowl and associated structure of an earthmoving scraper embodying the invention;

FIGURE 2 is a plan view of the scraper structure of FIGURE 1; and

FIGURE 3 is an additional side elevational view of the scraper structure of FIGURE 1 showing certain mechanisms thereof in moved positions for the purpose of facilitating loading of the scraper.

Referring now to the drawing and more particularly to FIGURES l and 2 in conjunction, a scraper of the class to which the invention is applicable has a load carrying bowl 11 generally formed by a floor 12, sidewalls 13, and with the rear wall being formed by a movable ejector 14, the top and the forward face of the bowl being open. The cutting edge is formed by a blade 16 extending forwardly and downwardly from the front edge of floor 12. The bowl 11 is supported at the back end by frame members 17 which extend to the rear wheel assembly 18 of the scraper. The bowl 11 is supported at the forward end by a pair of draft arms 19 which extend from a tractor hitch 21 back along each side of the bowl and which are connected thereto by pivots 22 situated at a central position on the bowl sidewalls 13. The tractor which draws the scraper through hitch 21 and the rear wheel assembly 18 of the scraper may be of conventional construction and accordingly will not be herein described.

The bowl sidewalls 13 extend a substantial distance forward from the position of the cutting edge 16 and a cross beam 23 extends between the two sidewalls at the forward end thereof and at a level well above that of the cutting edge. Raising and lowering of the bowl 11 is effected by a pair of hydraulic jacks 24 connected between the cross beam 23 and a pair of arms 26 projecting rearwardly and upward from the tractor hitch 21. Extension of jacks 24 thus pivots the entire bowl assembly 11 downward about the axis of rear wheels 18 to cause the cutting edge 16 to bite into the ground surface 27. Forward motion of the scraper then causes a superficial layer of earth to be carried up over the edge 16 and into the bowl 11. When the bowl 11 has been filled jacks 24 are contracted pivoting the bowl upward about rear wheels 18 into the load carrying position at which the scraper may travel at a relatively high speed to transport the earth away from the site. Discharge of the contents of the bowl 11 is accomplished by extension of a second pair of jacks 28, connected between the ejector 14 and the rear wheel assembly 18, which move the ejector forward towards the cutting edge 16.

In order to utilize completely the load carrying capacity of the bowl 11, means must be provided to hold the material therein at the open forward end. In a conventional scraper a singly pivoted apron closure is used for this purpose and most self loading scrapers employ an earth elevator extending upwardly at the front of the bowl.

This invention provides an apron 29 carried on an articulated support assembly 31 which provides for manipulation of the apron forwardly and rearwardly, up and down and angularly with respect to an axis transverse to the bowl 11. Any combination of these movements may be made simultaneously so that the apron 29 may be maneuvered in what ever manner may be desirable to facilitate scooping of material into the bowl 11 and to assist other scraper operations.

Considering now the detailed structure of apron support assembly 31, a pair of arms 32 are situated one on each side of the bowl 11 with the lower end of each arm being coupled thereto by pivots 33. A cylindrical cross member 34 connects the opposite end of arms 32 above the bowl sidewalls 13 which preferably have a circular profile at the upper edge to maximize load carrying capacity while providing for pivoting of the arms 32 and cross member 34 about pins 33.

An extension 36 projects a short distance from the upper end of each arm 32, at an angle with respect thereto, to pivotally connect with one end of an intermediate frame section 37 at pivots 38. Frame section 37 is formed by side members 39 which are connected by a series of transverse tubular reinforcing members 42. In addition to reinforcing the intermediate frame section 37, the tubular cross members 42 serve to aid in retaining material at the forward end of the bowl 11 when the apron 29 is moved to the load carrying position. Apron 29, which has an arcuate profile, is coupled to the end of intermediate frame section 37 opposite pivots 38 by an additional set of pivots 43 near the upper edge of the apron.

Thus complete flexibility of movement of the apron 29 in the forward, rearward, vertical, and angular directions is afforded inasmuch as the apron may be pivoted with respect to intermediate frame 37, which in turn may pivot with respect to the arms 32, and the arms 32 are in turn pivotable about a transverse axis through the bowl. Mechanism for effecting and controlling such motion includes a first pair of double acting hydraulic jacks 44 each being coupled to one of the arms 32 at a pivot 46 situated at an intermediate point therealong and being coupled at the opposite end to a side wall 13 of the bowl 11 at a pivot 47 situated rearwardly from the pivot 46. Extension of jacks 44 therefore pivots the arms 32 forwardly while retraction of the jacks 44 swings the arms to the rear.

Pivoting of the intermediate frame section 37 relative to arms 32 is controlled by a second pair of jacks 48 each of which is connected between a pivot 49 at an intermediate point on one of the arms 32 and a pivot 51 on one of a pair of triangular pivot bracket assemblies 52 secured to the intermediate frame section 37 at the end thereof closest to arms 32. A pair of stops 55 secured to the brackets 52 and side members 39 are positioned to contact the top edges of the bowl side walls 13 to limit inward pivoting of the apron assembly.

A corner of each pivot bracket 52 projects upwardly and an end of one of a third pair of double acting bydraulic jacks 53 is pivotally coupled thereto. The opposite end of each jack 53 is pivoted to an arm 54 which extends a short distance upward from the apron 29. Thus the third set of jacks 53 may be utilized to pivot the apron 29 with respect to the intermediate frame section 37. The three sets of hydraulic jacks 44, 48 and 53 are preferably controlled from the operators station of the tractor which draws the scraper, suitable control systems for such jacks being understood within the art.

Considering now typical manipulations of the apron 29 which may advantageously be made during operation of the scraper, extension of jacks 44 accompanied by a partial extension of jacks 48 and 53 will position the apron 29 at the cutting blade 16 with the upper edge of the apron being situated above and forwardly therefrom as illustrated in FIGURE 1 in particular. This is the normal position of the apron for transporting a load. Referring now to FIGURE 3 further extension of jacks 48, generally accompanied by contraction of jacks 53, positions the lower edge of the apron 29 forwardly from the cutting edge 16 and slightly above the cutting edge so that the edge may bite into the surface soil layer 27 and guide soil backwardly into the bowl 11. At this stage of operation soil will tend to mound up immediately above the cutting edge 16 and movement of such soil back into the bowl 11 may be assisted by contracting jacks 44 and 48 while extending jacks 53 so that the apron 29 performs a kind of scooping motion back into the position illustrated at 29. This movement of the apron 29 may be cyclically repeated during loading of the scraper bowl 11 while the scraper is in motion, and will generally eliminate any need for use of a pusher tractor with the scraper.

Referring now again to FIGURE 1, the availability of the kind of apron motion described above facilitates an advantageous use of the ejector 14 to assist loading. In particular, at the start of loading the jacks 28 may be actuated to move ejector 14 forward so that the lower edge of the ejector is adjacent the cutting blade 16. Apron 29 may then be manipulated to load soil onto the ejector 14 after which jacks 28 are contracted to draw the ejector to the rear of the bowl carrying the soil with it. Thus in contrast to a conventional scraper the initial loading is at the rear of the bowl leaving the forward portion unobstructed and capable of receiving additional soil without resistance. Ejector 14 preferably has sidewalls 56 to facilitate such use of the ejector in carrying material to the rear of the bowl 11.

During discharge of the soil from bowl 11 apron 29 may be lifted completely above the bowl by contracting jacks 44 while extending jacks 48 as illustrated at 29" in FIGURE 1. Ejector 14 may then be driven forward by extension of jacks 28 to force the contents of the bowl out of the open forward end thereof. Should soil or other materials stick to the ejector 14, jacks 48 and 53 may be progressively contracted while jacks 44 are gradually extended to cause the lower end of apron 29 to sweep downward and forward along the face of the ejector and forcibly wipe lodged material therefrom.

It will be apparent that by the appropriate operation of the several jacks 44, 48 and 53 various other operations may be accomplished. For example the apron 29 may extend forwardly from the cutting edge 16 above some large object such as a boulder and may then be utilized to draw the object back and up into the bowl 11.

While the invention has been disclosed with respect to a specific embodiment for purposes of example it will be apparent that numerous modifications are possible within the scope of the invention and it is not intended to limit the invention except as defined in the following claims.

What is claimed is:

1. In an earthmoving scraper of the class having a scraper body with a load carrying bowl which is open at the front end and having a cutting edge for guiding material into said bowl as said scraper moves forwardly, a mechanism for facilitating loading and other operations comprising, in combination, an apron member disposed transversely with respect to said bowl, an articulated apron support extending between said bowl and said apron an-d having at least first and second sections with a first pivot connection therebetween, a second pivot connection coupling said apron to said first support section, a third pivot connection coupling said second support section to said scraper body, first actuating means having an end connected to said apron and another end connected to said first section for pivoting said apron with respect to said first support section about said second pivot connection independently of pivoting motion about said first and third pivot connections, second actuating means having an end connected to said first section and another end connected to said second section for pivoting said first section of said support relative to said second section thereof about said first pivot connection independently of pivoting motion about said second and third pivot connections, and third actuating means having an end connected to said second section and another end connected to said scraper body for pivoting said second support section relative to said bowl about said third pivot connection independently of pivoting motion about said first and second pivot connections.

2. Mechanism as defined in claim 1 wherein said third pivot connection is situated above said cutting edge and rearwardly therefrom.

3. Mechanism as defined in claim 2 wherein said first and second sections of said support have a combined length exceeding the distance between said third pivot connection and said cutting edge whereby said apron may be moved forwardly from said cutting edge.

4. Mechanism as defined in claim 2 wherein said first and second sections of said support have a combined length which exceeds the distance from said third pivot connection to the top of said bowl by an amount at least equal to the height of said apron whereby said apron may be lifted above said bowl while in a substantially upright orientation.

5. Mechanism as defined in claim 1 wherein said second section of said apron support is comprised of a pair of arms each extending along an opposite side of said bowl and being coupled thereto by said third pivot connection.

6. Mechanism as defined in claim 5 wherein a cross member extends between said arms at the ends thereof remote from said third pivot connection and wherein the sidewalls of said bowl have an arcuate profile at the .upper edge conforming to the arc traveled by said cross member as said arms are pivoted whereby the load carrying capacity of said bowl is maximized while providing for maximum manipulatability of said apron.

7. Mechanism as defined in claim 1 wherein said first section of said apron support is a framework extending transversely for substantially the full width of said bowl whereby said first section in conjunction with said apron may be positioned to retain material in said bowl at said open forward end thereof.

8. Mechanism as defined in claim 1 wherein said first and second and third actuating means are double acting fiuid operated jacks.

9. Mechanism as defined in claim 1 wherein said first section of said apron support is comprised of a pair of side members each coupled to said apron by said second pivot connection and which are spaced apart a distance less than the width of said bowl whereby said apron and first support section may be manipulated within said bowl, and wherein said second section of said apron support is comprised of a pair of arms each extending along an opposite side of said bowl and being coupled to one of said first section side members by portions of said first pivot v connection which are transverse to the sides of said bowl.

10. Mechanism as defined in claim 9 wherein said first actuating means comprises a first pair of double acting hydraulic jacks each being connected between said apron and one of said side members of said first section of said apron support, and wherein said second actuating means comprises a second pair of double acting hydraulic jacks each being coupled between one of said arms and one of said side members of said first section of said apron support and wherein said third actuating means is comprised of a third pair of double acting hydraulic jacks each being connected between one of said arms and said scraper body.

References Cited UNITED STATES PATENTS 2,207,424 7/1940 Wood 37-126 2,795,872 6/1957 Wardle 37-126 3,052,996 9/1962 Holopainen 37-1'24 XR 3,060,601 10/ 1962 Reynolds 37-126 3,067,888 12/1962 Reynolds 37-126 XR 3,105,311 10/1963 Hait 37-126 XR 3,221,424 12/ 1965 Hancock 1 37-129 3,235,983 2/1966 Wilson 37-126 3,235,984 2/ 1966 Wilson 37-126 EDGAR S. BURR, Primary Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,471 ,952 October 14 Robert A. Peterson It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 64, after "wherein" insert the pivot axis of line 65, after "is" insert fixed relative to said bowi and is Signed and sealed this 10th day of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

